While most clinicians view substance use as a chronic relapsing condition that may require multiple episodes of care, most research to date has focused on single episodes of care. Recent emphasis on outcome based contracts and/or capitated cost contracts has stimulated interest in better managing clients "across" multiple admissions and/or in a continuum of care model. In the treatment of other chronic illnesses quarterly, semi-annual or annual check-ups are often integral parts of aftercare which check for early indications of relapse and attempt early re-intervention before the condition and consequences worsen. The specific aims of this study are to determine the relative effectiveness of an Early Re-Intervention (ERI) protocol in terms of its ability to: 1) reduce the time to treatment re-entry and increase the rates of early treatment re-entry, and, 2) improve long-term outcomes related to a) substance use, HIV risk behaviors, illegal activity, b) training- and employment-related behaviors, and c) utilization of expensive services (e.g., inpatient substance abuse treatment, inpatient mental health treatment, emergency room admissions, hospital nights, days in jail, days of their children being in foster care or institutions). To evaluate ERI, 800 new clients with substance use disorders will be recruited from two central intake units, one located in Chicago and another in Central Illinois. Clients will be blocked into one of five severity groups (based on drug dependence, alcohol dependence, and frequency of use) then randomly assigned to either quarterly outcome monitoring (OM) with 20-30 minute assessments for 18 months or quarterly OM plus ERI. Response of participants in the ERI condition will be used to determine the participants linkage assistance needs every quarter. ERI Linkage Managers will provide the qualified participants with linkage assistance including feedback on their current substance use and need for treatment, motivational discussions to convince them to consider returning to treatment, and then direct assistance in helping them make and keep a readmission appointment. Through feedback, social reinforcement, and assistance to access care, ERI is expected to reduce the time to readmission, increase the rate of early treatment re-admissions, and consequently, improve long-term outcomes. Significant findings in favor of the ERI protocol would provide a better understanding of the clinical value of outcome monitoring and a straightforward, replicable protocol for improving the long-term effectiveness of drug treatment.